#include<stdio.h>
#include<stdlib.h>
#include<windows.h>
int main()
{
    int i,j;
    int x=0;
    int y=5;
    int velocity_x=1;
    int velocity_y=1;
    int left=0;
    int right=20;
    int top=0;
    int bottom=10;

    while(1)
    {
        x+=velocity_x;
        y+=velocity_y;
           system("cls");
           for(i=0;i<x;i++)
           printf("\n");
         for(j=0;j<y;j++)
           printf(" ");
         printf("o\n");
         Sleep(50);
         if((x==top)||(x==bottom))
            velocity_x=-velocity_x;
         if((x==left)||(x==right))
            velocity_y=-velocity_y;
    }
    return 0;
}
